Shank piece and method of making the same



Marchzs, 1939. RQLMRD 2,151,977

SHANK PIECE AND METHOD OF MAKING THE SAME Filed Feb. 5, 1957 rl YIn making shank pieces of the type referred to operated to form the spurs so that, as the tacks ll() Patented Mar. 28,1939 v s UNITED sTsTss SHANK PIECE AND METHOD OF MAKING THE SAME Renfrew D. Laird, Brockton, Mass., assigner, by mesne assignments, to United Shoe Machinery Corporation, Paterson, N. J., a corporation of New Jersey Application February 5, 1937, Serial No. 124,280 4 Claims. (Cl. 12146) This invention relates to improvements in up a plurality of spurs adjacent to the edges of shank pieces and to improved methods oi makthe tack holes in the stiffener strip at its outer or ing shank pieces. The invention is herein illus* lower side, i. e., the side which is to face the filler trated in its application to the manufacture of piece, and to embed these spurs in the substance fabricated or composite shank pieces of the type of the filler piece in the operation of tacking the -5 comprising a liller piece of relatively soft mastiifener strip thereto and thus positively to preterial, such as berboard or leatherboard, and a vent any relative creeping of the parts. As heremetallic stiiener strip which is secured by means in illustrated, the tack-receiving holes in the of tacks to the ller piece. stiffener strip are made by punches shaped and the tacks arey passed through tack holes previare being driven, the shanks of the tacks will be ously punched in the metallic strip and after the tightly and firmly gripped by the spurs and thus points of the tacks have been driven through the securely held against any tendency to become filler` piece they are bent over and clenched loosened relatively to the stiifener strip. Thus, against the lower surface of the latter. The tackeven though the tacks may subsequently become ing of the st-iiener strip to the filler piece may somewhat loosened in the ller piece, there will be accomplished by hand or by machinery and in be noy play between the tacks and any portions order that the points of the tacks shall be entered of the metallic stiifener strip and consequently no within the tack holes in the stiffener strip and the possibility that any objectionable metallic noises tacks properly positioned for the tack driving will be produced after the shank piece has been A29 operation it has been customary to make the tack incorporated in a shoe. As also illustrated, the holes substantially larger than the shanks of the tack holes are formed ywith flaring or belltacks. Consequently, after the tacks have been mouthed openings at the upper side of the stiffdriven there is considerable space between the ener strip and the heads of the tacks are counter- Shanks of the tacks and the edges of the tack sunk in these openings as a result of the tack- 2 holes. When a shoe having such a shank piece is driving operation so that the upper surfaces of A being worn the movements of the foot tend to the tack heads are substantially fiush with the bend or flex the shank piece and thus to cause upper surface of the stirener strip and thus have the Stiiener strip and the ller piece to creep no tendency to produce undesirable protuberback and forth relatively to each other in direcances. In practice, and as herein illustrated, the ,3.0 tionsI lengthwise of the shoe so as repeatedly to points of the tacks are bent over and clenched 'v take up and restore the play between the Shanks against the lower surface of the filler piece so of the tacks and the edges of the tack holes. that the bent-over points will tend to prevent any Moreover, continued wear of the shoe has some substantial loosening of the ta-cks in the filler tendency to loosen the tacks so as eventually to piece and will serve to maintain the spurs of the 35 provide play` between the stifener strip and the stiirener strip embedded in the ller piece to heads of the tacks. These conditions are uncounteract any influences tending to cause the desirable inasmuch as objectionable metallic or parts of the shank piece to creep relatively to one clicking noises are liable to be made when poranother.

40 tions of the stiffener strip strike against the tacks. The invention will now be described with refer- .49

It is even possible, as a result of the necessary ence to the accompanying drawingin which handling 0f the Shank DeCeS incident t0 packing Fig. l is a perspective View of the stiener strip and shipping, for the parts of some of the shank Showing the upper Side thereof; pieces to become loosened so that they will chat- Fig` 2 is a View in longitudinal section and on teror rattle, a condition tending to make it appear that the manufacture of the shank pieces l Ilfrlrlenicmphshed Wlth the proper care Fig. 3 is a sectional view, on an enlarged scale,

One object of the present invention is to insure take@ Onthe hue IH"HI of F 1g' against such undesirabley conditions as those Fig* 4 1S a fragmentary PETSPBCVSWSW 011 50 above referred to and to insure that the compo- Still further enlarged Scale 0f a port/10H 0f the nent parts of the Composite Shank pieces 5119,11 S'llenel Strip DOSOlied With its lOWeI' Side remain tightly secured together so long as the uppermost to show the spurs that are struck up shank pieces are in use. adjacent to one of the tack holes;

With this object in View it is proposed to strike Figs. 5 and 6 are perspective views similar to *55 an enlarged scale illustrating the operation of 4-5 forming a tack hole in the stiiener strip;

Fig. 4 but showing modified constructions and arrangements of the spurs;

Fig. '7 is a view, partially in cross-section and partially in elevation, illustrating the operation of tacking a stiiener strip to a ller piece;

Fig. 8 is a sectional view, on an enlarged scale, taken along the line VIII-VIII of Fig. 7;

Fig. 9 is a perspective view of the completed shank piece showing the upper side thereof;

Fig. 10 is a sectional view, on an enlarged scale, taken along the line X--X of Fig. 9; and

Fig. 11 is a perspective view of the shank piece showing the lower side thereof.

As shown in the drawing, the improved shank piece comprises a filler piece Hl and a stiffener strip I6 which is secured to the filler piece by means of tacks I8 the heads 2li of which engage the upper side of the stiffener strip and the pointed ends 22 of which are clenched against the lower surface of the filler piece. The filler piece I4 may advantageously be made of such material as leatherboard or berboard and, as shown, is shaped in outline to i'it within and substantially fill the space between the edges of the cverlasted margins of a shoe upper. The stiffener strip I6 may consist of a narrow strip of hardened steel having the usual or any desired amount of longitudinal curvature.

The stiffener strip i6 is provided with tack holes 2l! which are preferably located in or near the opposite end portions of the strip. The tack holes are preferably made in the stiffener strip before the steel is hardened and in such a manner as to form flaring or bell-mouthed openings 26 (Fig. 3) at the upper side of the strip and to strike up more or less sharply pointed spurs or prongs 28 at the lower side of the strip adjacent to the edges of the hole. The tack holes may conveniently be formed by means of punches such, for example, as the punch 3E] (Fig. 1) having more or less tapered or rounded end portions, the punches operating in conjunction with a work support (such as the anvil 32) having suitable openings registering with the punches. The tack holes 24 are made large enough to receive the tacks readily and the flaring upper portions at least of the holes are made substantially larger than the shanks of the tacks to facilitate the entrance of the tacks into the holes and to enable the heads of the tacks to be practically countersunk within the tack holes by the blows of the tack drivers so that the upper surfaces of the heads will be nearly or substantially iiush with the upper surface of the stiifener strip and thus will have no tendency to form undesirable humps or ridges. The punching of the tack holes may result in the striking up of two, three or more spurs adjacent to the edges of' the holes at the outer or lower side of the strip and the eX- tent of the penetrating or puncturing strokes of the punches is regulated so that the lower, more or less sharp and pointed ends of the spurs will be disposed so as to engage and tightly to grip the shanks of the tacks as the latter are being driven through the holes. It has been found practicable and desirable to regulate the punching operation so as to form only two oppositely disposed spurs, such as those shown at 28 in Figs. 3 and 4, or so as to form three spurs shaped and arranged substantially as indicated at 280 in Fig. 6. In instances where only two spurs are formed they may be disposed relatively to the strip as indicated in Fig. 4 or as in Fig. 5. After the punching operation has been completed the stifener strips are preferably subjected to the usual hardening operation which hardens the strips, including the spurs, to such an extent that the driving of the tacks will not appreciably alter the shape of the spurs or spread them apart.

In attaching a stiffener strip to a filler piece these parts may conveniently be assembled upon a work support, such as an anvil 36 (Fig. '7), having recesses 38 so arranged as to register with the Shanks of the tacks and so shaped as to clench the points of the tacks against the filler piece. The tacks, after having been positioned with their pointed ends within or in line with the tack holes in the stiifener strip, are driven through the holes and through the ller piece by means of devices such as the illustrated driver 40. The tacks are preferably made of soft ductile material as in accordance with the usual practice and tacks are selected of a size such that as they are being driven they will have to be forced or wedged through the restricted openings between the lower ends of the spurs so as to insure that the spurs will grip or clutch the shanks of the tacks and thus function positively to hold the tacks againstany subsequent heightwise movement relatively to the stiffener strip after the tacks have once been driven into place. In practice it has been found that the sharp end or edge portions of the hardened spurs actually bite or plow into the relatively soft metal of the tacks so that they may actually form furrows in the shank portions of the tacks, the furrows extending lengthwise of the shank portions as indicated at 42 in Figs. '7 and 8, and thus hold the tacks most effectively against both heightwise and turning movements. The force of the blows delivered by the tack drivers is sufficient to embed the individual spurs quite deeply into the substance of the ller piece and thus to insure against any relative creeping of the stiffener strip and the filler piece. Moreover, the tack-driving operation results in causing the ends of the tacks to be clenched against the lower surface of the filler piece and the heads of the tacks to become practically countersunk within the flaring openings of the tack holes, as best indicated in Fig. 7.

It will be seen that the gripping of the tacks by the spurs positively prevents loosening of the tacks so as to insure that there will be no play between the tacks and the stiffener strip and consequently no objectionable clicking or metallic noises such as that above referred to. Moreover, the shank piece itself, inasmuch as its component parts are maintained iirmly and tightly secured together, is a more workmanlike article of manufacture and one which is better adapted for its intended purpose.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A fabricated shank stiffener unit comprising a non-metallic ller piece, a hardened steel stiffener strip disposed in face-to-face engagement with said filler piece and having a plurality of tack-receiving holes therein, a group of pointed spurs struck up from said strip and projecting from its outer or lower side around each of said holes and embedded within the material of said filler piece, and headed tacks of soft ductile material, one in each of said holes, the Shanks of said tacks extending through said iiller piece and having urrows extending lengthwise thereof and said. spurs iirmly gripping the Shanks of said tacks within said furrows to hold the tacks against both heightwise and turning movements.

2. A fabricated shank stiffener unit comprising a non-metallic filler piece, a hardened steel stifener strip disposed in face-to-face engagement with said ller piece and having a plurality of bell-mouthed tack-receiving holes therein, a group of pointed spurs struck up from said strip and projecting from its lower side around each of said holes and embedded within the material of said ller piece, and headed tacks, one arranged in each of said holes with its head seated within the bell-mouthed portion of the hole, said tacks having furrowed shank portions extending through said filler piece and clenched over against the outer side thereof and said spurs extending into the furrows in the shank portions of said tacks to hold the tacks from turning.

3. That improvement in methods of making fabricated shank stiiener units which consists in puncturing .a steel stiffener strip at a plurality of points thereby forming a plurality of tack-receiving holes in the strip and in the puncturing operation striking up a group of pointed spurs adjacent to each of said holes, hardening said strip, assembling the hardened strip and a relatively soft ller piece in face-to-face relation with the spurred side of the strip facing the ller piece, and driving headed tacks of soft ductile material through said holes and through said ller piece and in said tack-driving operation n individually embedding said spurs within the material of the ller piece and wedging the soft shanks of the tacks between the hardened points of said spurs so that they will be tightly gripped by the spurs.

4. That improvement in methods of making fabricated shank stiiener units which consists in punching a plurality of bell-mouthed tack-receiving holes in an unhardened steel stiifener strip and in the course of said operation striking up a group of downwardly converging spurs adjacent to each of said holes, hardening said strip, assembling said strip and a ller piece of brous sheet material in face-to-face relation with the spurred side of the strip facing the ller piece, and driving headed tacks of soft metal through said holes and through said ller piece and in the course of said operation embedding said spurs in the filler piece, seating the heads of the tacks within the bell-mouthed portions of said holes, wedging the soft Shanks of the tacks tightly between the hardened points of said spurs thereby causing the spurs tightly to grip the tacks, and clenching the points of the tacks against the outer side of the filler piece.

RENFREW D. LAIRD. 

